Fig. 2. The for^s allele results in a transport phenotype in tubules. Fluid secretion assays were performed on intact tubules from 7-day-old adult for^R and for^s flies. Basal rates of secretion were measured and capa-1 (10^-7 mol l^-1) (Kean et al., 2002) added at 30 min (arrow). Secretion rates were monitored for a further 30 min. Fluid secretion rate (nl min^-1) are means ± S.E.M. (N=8) for for^R tubules (broken line) and for^s tubules (solid line). ^*P<0.05, using t-tests on experimental versus control at each time point separately.